The invention relates to a method and assembly for cutting a wide variety of sheet metal stock, such as angle irons, square tubing, round tubing and bars, channels, flat bars, H-beams, T-beams, and the like.
In the shearing of steel stock, under some circumstances the edges of the stock being cut tend to roll during the cutting operation, providing an end product that is not entirely satisfactory. According to the present invention, a method and structure are provided which positively prevents such rolling in a simple and efficient manner. Cooperating male and female dies are utilized, the male die including a cutting blade with a shelf member provided on each face of the cutting blade for engaging the edges of the material being sheared. The cutting blade is moved through the metal piece being cut so that the shelf members engage the edges of the metal piece sheared by the cutting blade. The stroke of the male die with respect to the female die is positively controlled so that the shelf members and female die are spaced apart a distance corresponding to the thickness of the metal piece being cut when the stroke is completed. Thus, the rolling of the edges is prevented.
Since it is desirable to be able to cut a wide variety of different types of steel stock utilizing the same basic actuating mechanism, it is desirable to mount a plurality of male-female die groups so that a selected group can readily be moved into place in cooperation with an actuating element, the steel stock being fed to the selected die group. According to the present invention, a plurality of die groups are mounted around the perimeter of a rotatable wheel, and radial bores formed in the wheel. Each die group is readily removable from its respective bore by merely pulling a pair of spring-pressed dogs against the bias of the springs, the dogs preventing movement of the die group out of its respective bore in one position, and allowing relative movement therebetween in the released position. Each male-female die group has a disposal chute associated therewith leading to an opened central portion on one side of the wheel containing the dies so that any material severed from the stock during shearing is moved away from the male and female dies. Suitable stop means are associated with the male dies to prevent them from moving out of operative association with the female dies during rotation of the wheel containing the dies.
It is the primary object of the present invention to provide an improved steel stock cutting method and assembly. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.